In communications networks such as LANs (local area networks), typical LAN switches relay received data to ports corresponding to destination information, such as MAC (media access control) addresses, set in the header portions of the data.
With respect to LAN switches, for example, Japanese Unexamined Patent Application Publication No. 2000-253035 discusses a technology in which, of ports coupled to communication control means of multiple systems, ports from which data inputs are detected are collectedly coupled to the communication control means of one of the systems and supply of power to the remaining communication control means is stopped.